Velocity Signalling Line Circuit Module


Key Features

  • Supports up to 254 addresses
  • Quick and easy to install
  • Double address detection
  • Supports Class X and Class A wiring configurations
  • Time saving AUTO-LEARN facility


The Velocity Signalling Line Circuit (SLC) Module provides power for, and handles communications to, the analogue addressable devices in a Velocity fire detection system.

Velocity SLC continually monitors the analogue values of all the connected devices and shows it as a percentage of the alarm threshold value on the control panel. Each installed SLC can accommodate up to 254 addresses and devices can be soft addressed using the VDOT-AD2 handheld programming tool; this reduces the risk of error and saves a significant amount of time compared to traditional hard addressing.

Velocity’s AUTO-LEARN feature also saves time and effort by allowing the system to learn for itself what devices have been installed when installing a new loop or changing device configurations.

Velocity SLC Module is quick and easy to install and is designed to support Class X and Class A wiring configurations. It has a “heartbeat” LED that shows communication between the module and the motherboard.


All components in the Velocity range are UL certified and comply with the requirements of Underwriters Laboratories (UL) 864 Control Units and Accessories for Fire Alarm Systems 10th Edition.

Tech Specs

Design StandardUL864 10th Edition
ApprovalUL Laboratories
Rated Voltage35V DC Nominal (24V – 39V)
Maximum SLC Current200mA or 500mA
Maximum SLC Resistance at 200mA50Ω (25Ω per core)
Maximum SLC Resistance at 500mA20Ω (10Ω per core)
Maximum SLC Capacity254 Addresses
Maximum SLC Cable Length2km (Depending on what cable size is used. A 2km Maximum SLC distance is assuming 2.5mm2 (14AWG) Cable is used)
Maximum SLC Capacitance100nF
Maximum SLC Baud Rate4334 bits per second (typical)
Maximum Ground Fault Impedance10KΩ
Wiring ClassClass X or Class A [Power Limited & Supervised]
Operating Temperature0°C (32°F) to 49°C (120°F)
Max Humidity93% Non-Condensing
Dimensions (W x H x D)57mm x 105mm x 47mm
Recommended Cable Sizes18 AWG to 14 AWG (0.8mm²)